Various attempts have been made at providing safety mechanisms in buildings which alert the occupants thereof to fire through the detection of smoke. However, the fact that people have become alerted to the presence of smoke does not necessarily enable their evacuation or prevent property damage due to smoke. The majority of fire related deaths, approximately eighty (80%) percent are due to smoke inhalation and not the fire directly.
The mere presence of smoke, regardless of the inhabitants awareness of it, is dangerous. Smoke causes property damage, it is difficult to see through and obviously creates breathing problems making evacuation from a smoke filled environment difficult.
In the event that additional time is needed to evacuate small children, handicapped persons, or elderly persons from a burning building, the occupants of the building and/or rescuers are placed in jeopardy of smoke inhalation. Further, the decreased visibility due to the smoke further hampers evacuation and extermination of the fire.
Thus, simply alerting occupants to the existence of smoke is not enough to eradicate all of the problems caused by smoke in a building.
Further there are instances where the removal of smoke from a building is preferably accomplished without alarming the occupants thereof. In the case of restaurants, bars, lounges, dance halls and such places where there is likely to be an accumulation of smoke due to cigarettes, cigars, or pipes, there is no need for an alarm, yet the removal of the smoke once it has reached a predetermined level, is desirable. As of now, there is no method of detecting smoke in an alarmless fashion and providing for its removal.